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;;; -*- Log: code.log; Package: Lisp -*-
;;; ### Some day fix to accept :wild in any pathname component.
;;; **********************************************************************
;;; This code was written as part of the Spice Lisp project at
;;; Carnegie-Mellon University, and has been placed in the public domain.
;;; If you want to use this code or any part of Spice Lisp, please contact
;;; Scott Fahlman (FAHLMAN@CMUC). 
;;; **********************************************************************
;;;
;;; Ugly pathname functions for Spice Lisp.
;;;    these functions are part of the standard Spice Lisp environment.
;;;
;;; Written by Jim Large and Rob MacLachlan
;;;
;;; **********************************************************************
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(export '(pathname pathnamep *default-pathname-defaults* truename
	  parse-namestring merge-pathnames make-pathname
	  pathname-host pathname-device pathname-directory
	  pathname-name pathname-type pathname-version
	  namestring file-namestring directory-namestring
	  host-namestring enough-namestring user-homedir-pathname
          probe-file rename-file delete-file file-write-date
	  file-author directory))

(use-package "EXTENSIONS")

(in-package "EXTENSIONS")
(export '(print-directory complete-file ambiguous-files default-directory
			  file-writable))
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;;; Pathname structure


;;; *Default-Pathname-defaults* has all values unspecified except for the
;;;  host.  All pathnames must have a host.
(defvar *default-pathname-defaults* ()
  "Set to the default pathname-defaults pathname (Got that?)")

(defun filesys-init ()
  (setq *default-pathname-defaults* 
	(%make-pathname "Mach" nil nil nil nil nil)))


;;; The pathname type is defined with a defstruct.
;;; This declaration implicitly defines the common lisp function Pathnamep
(defstruct (pathname
	    (:conc-name %pathname-)
	    (:print-function %print-pathname)
	    (:constructor
	     %make-pathname (host device directory name type version))
	    (:predicate pathnamep))
  "Pathname is the structure of the file pathname.  It consists of a
   host, a device, a directory, a name, and a type."
  (host nil :type (or simple-string null))
  (device nil :type (or simple-string (member nil :absolute)))
  (directory nil :type (or simple-vector null))
  (name nil :type (or simple-string null))
  (type nil :type (or simple-string null))
  (version nil :type (or integer (member nil :newest))))

(defun %print-pathname (s stream d)
  (declare (ignore d))
  (format stream "#.(pathname ~S)" (namestring s)))

(defun make-pathname (&key defaults (host nil hostp) (device nil devicep)
			   (directory nil directoryp) (name nil namep)
			   (type nil typep) (version nil versionp))
  "Create a pathname from :host, :device, :directory, :name, :type and :version.
  If any field is ommitted, it is obtained from :defaults as though by 
  merge-pathnames."
  (if defaults
      (let ((defaults (pathname defaults)))
	(unless hostp
	  (setq host (%pathname-host defaults)))
	(unless devicep
	  (setq device (%pathname-device defaults)))
	(unless directoryp
	  (setq directory (%pathname-directory defaults)))
	(unless namep
	  (setq name (%pathname-name defaults)))
	(unless typep
	  (setq type (%pathname-type defaults)))
	(unless versionp
	  (setq version (%pathname-version defaults))))
      (unless hostp
	(setq host (%pathname-host *default-pathname-defaults*))))

  (when (stringp directory)
    (setq directory (%pathname-directory (parse-namestring directory))))
  (%make-pathname
   (if (stringp host) (coerce host 'simple-string) host)
   (if (stringp device) (coerce device 'simple-string) device)
   directory
   (if (stringp name) (coerce name 'simple-string) name)
   (if (stringp type) (coerce type 'simple-string) type)
   version))


;;; These can not be done by the accessors because the pathname arg may be
;;;  a string or a symbol or etc.

(defun pathname-host (pathname)
  "Returns the host slot of pathname.  Pathname may be a string, symbol,
  or stream."
  (%pathname-host (if (pathnamep pathname) pathname (pathname pathname))))

(defun pathname-device (pathname)
  "Returns the device slot of pathname.  Pathname may be a string, symbol,
  or stream."
  (%pathname-device (if (pathnamep pathname) pathname (pathname pathname))))

(defun pathname-directory (pathname)
  "Returns the directory slot of pathname.  Pathname may be a string,
  symbol, or stream."
  (%pathname-directory (if (pathnamep pathname) pathname (pathname pathname))))

(defun pathname-name (pathname)
  "Returns the name slot of pathname.  Pathname may be a string,
  symbol, or stream."
  (%pathname-name (if (pathnamep pathname) pathname (pathname pathname))))

(defun pathname-type (pathname)
  "Returns the type slot of pathname.  Pathname may be a string,
  symbol, or stream."
  (%pathname-type (if (pathnamep pathname) pathname (pathname pathname))))

(defun pathname-version (pathname)
  "Returns the version slot of pathname.  Pathname may be a string,
  symbol, or stream."
  (%pathname-version (if (pathnamep pathname) pathname (pathname pathname))))



;;;; PARSE-NAMESTRING and PATHNAME.
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;;; SPLIT-FILENAME -- internal
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;;;
;;; Splits the filename into the name and type.  If someone wants to change
;;; this yet again, just change this.
;;; 
(defun split-filename (filename)
  (declare (simple-string filename))
  (let ((posn (position #\. filename :from-end t)))
    (cond ((null posn)
	   (values filename nil))
	  ((or (zerop posn) (= posn (1- (length filename))))
	   (values filename ""))
	  (t
	   (values (subseq filename 0 posn)
		   (subseq filename (1+ posn)))))))

;;; DO-FILENAME-PARSE -- internal
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;;;
;;; Split string into a logical name, a vector of directories, a file name and
;;; a file type.
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;;;
(defun do-filename-parse (string &optional (start 0) end)
  (declare (simple-string string))
  (let ((end (or end (length string))))
    (let* ((directories nil)
	   (filename nil)
	   (absolutep (and (> end start) (eql (schar string start) #\/)))
	   (logical-name
	    (cond (absolutep
		   (setf start (position #\/ string :start start :end end
					 :test-not #'char=))
		   :absolute)
		  ((find #\: string
			 :start start
			 :end (or (position #\/ string :start start :end end)
				  end))
		   (let ((posn (position #\: string :start start)))
		     (prog1
			 (subseq string start posn)
		       (setf start (1+ posn))))))))
      (loop
	(unless (and start (> end start))
	  (return))
	(let ((next-slash (position #\/ string :start start :end end)))
	  (cond (next-slash
		 (push (subseq string start next-slash) directories)
		 (setf start
		       (position #\/ string :start next-slash :end end
				 :test-not #'char=)))
		(t
		 (setf filename (subseq string start end))
		 (return)))))
      (multiple-value-bind (name type)
			   (if filename (split-filename filename))
	(values (cond (logical-name logical-name)
		      (directories "Default"))
		(if (or logical-name directories)
		  (coerce (nreverse directories) 'vector))
		name
		type)))))

(defun parse-namestring (thing &optional host
			 (defaults *default-pathname-defaults*)
			 &key (start 0) end junk-allowed)
  "Convert THING (string, symbol, pathname, or stream) into a pathname."
  (declare (ignore junk-allowed))
  (let* ((host (or host (pathname-host defaults)))
	 (pathname
	  (etypecase thing
	    ((or string symbol)
	     (let ((string (coerce (string thing) 'simple-string)))
	       (multiple-value-bind (device directories name type)
				    (do-filename-parse string start end)
		 (unless end (setf end (length string)))
		 (make-pathname :host host
				:device device
				:directory directories
				:name name
				:type type))))
	    (pathname
	     (setf end start)
	     thing)
	    (stream
	     (setf end start)
	     (pathname (file-name thing))))))
    (unless (or (null host)
		(null (pathname-host pathname))
		(string-equal host (pathname-host pathname)))
      (cerror "Ignore it."
	      "Host mismatch in ~S: ~S isn't ~S"
	      'parse-namestring
	      (pathname-host pathname)
	      host))
    (values pathname end)))
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(defun pathname (thing)
  "Turns thing into a pathname.  Thing may be a string, symbol, stream, or
   pathname."
  (values (parse-namestring thing)))



;;; Merge-Pathnames  --  Public
;;;
;;; Returns a new pathname whose fields are the same as the fields in PATHNAME
;;;  except that () fields are filled in from defaults.  Type and Version field
;;;  are only done if name field has to be done (see manual for explanation).
;;;
(defun merge-pathnames (pathname &optional
				 (defaults *default-pathname-defaults*)
				 default-version)
  "Fills in unspecified slots of Pathname from Defaults (defaults to
  *default-pathname-defaults*).  If the version remains unspecified,
  gets it from Default-Version."
  ;;
  ;; finish hairy argument defaulting
  (setq pathname (pathname pathname))
  (setq defaults (pathname defaults))
  ;;
  ;; make a new pathname
  (let ((name (%pathname-name pathname))
	(device (%pathname-device pathname)))
    (%make-pathname
     (or (%pathname-host pathname) (%pathname-host defaults))
     (or device (%pathname-device defaults))
     (or (%pathname-directory pathname) (%pathname-directory defaults))
     (or name (%pathname-name defaults))
     (or (%pathname-type pathname) (%pathname-type defaults))
     (or (%pathname-version pathname)
	 (if name
	     default-version
	     (or (%pathname-version defaults) default-version))))))


;;;; NAMESTRING and other stringification stuff.

;;; %Dirstring  --  Internal
;;;
;;; %Dirstring converts a vector of the form #("foo" "bar" ... "baz") into a
;;;  string of the form "foo/bar/ ... /baz/"

(defun %dirstring (dirlist)
  (declare (simple-vector dirlist))
  (let* ((numdirs (length dirlist))
	 (length numdirs))
    (declare (fixnum numdirs length))
    (dotimes (i numdirs)
      (incf length (the fixnum (length (svref dirlist i)))))
    (do ((result (make-string length))
	 (index 0 (1+ index))
	 (position 0))
	((= index numdirs) result)
      (declare (simple-string result))
      (let* ((string (svref dirlist index))
	     (len (length string))
	     (end (+ position len)))
	(declare (simple-string string)
		 (fixnum len end))
	(replace result string :start1 position  :end1 end  :end2 len)
	(setf (schar result end) #\/)
	(setq position (+ end 1))))))

(defun quick-integer-to-string (n)
  (cond ((zerop n) "0")
	((eql n 1) "1")
	((minusp n)
	 (concatenate 'simple-string "-"
		      (the simple-string (quick-integer-to-string (- n)))))
	(t
	 (do* ((len (1+ (truncate (integer-length n) 3)))
	       (res (make-string len))
	       (i (1- len) (1- i))
	       (q n)
	       (r 0))
	      ((zerop q)
	       (incf i)
	       (replace res res :start2 i :end2 len)
	       (%primitive shrink-vector res (- len i)))
	   (declare (simple-string res)
		    (fixnum len i r))
	   (multiple-value-setq (q r) (truncate q 10))
	   (setf (schar res i) (schar "0123456789" r))))))
	   
(defun %device-string (device)
  (cond ((eq device :absolute) "/")
	(device
	 (if (string-equal device "Default")
	     ""
	     (concatenate 'simple-string (the simple-string device) ":")))
	(T "")))

(defun namestring (pathname)
  "Returns the full form of PATHNAME as a string."
  (setq pathname (pathname pathname))
  (let* ((directory (%pathname-directory pathname))
	 (name (%pathname-name pathname))
	 (type (%pathname-type pathname))
	 (result (%device-string (%pathname-device pathname))))
    (declare (simple-string result))
    (when directory
      (setq result (concatenate 'simple-string result
				(the simple-string (%dirstring directory)))))
    (when name
      (setq result (concatenate 'simple-string result 
				(the simple-string name))))
    (when (and type (not (zerop (length type))))
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      (setq result (concatenate 'simple-string result "."
				(the simple-string type))))
    result))

(defun %ses-get-useful-name (pathname)
  "NAMESTRING of pathname ignoring the device slot."
  (setq pathname (pathname pathname))
  (let* ((directory (%pathname-directory pathname))
	 (name (%pathname-name pathname))
	 (type (%pathname-type pathname))
	 (result ""))
    (declare (simple-string result))
    (when directory
      (setq result (concatenate 'simple-string result
				(the simple-string (%dirstring directory)))))
    (when name
      (setq result (concatenate 'simple-string result 
				(the simple-string name))))
    (when (and type (not (zerop (length type))))
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      (setq result (concatenate 'simple-string result "."
				(the simple-string type))))
    result))

;;; This function is somewhat bummed to make the Hemlock directory command
;;; is fast.
;;;
(defun file-namestring (pathname)
  "Returns the name, type, and version of PATHNAME as a string."
  (unless (pathnamep pathname) (setq pathname (pathname pathname)))
  (let* ((name (%pathname-name pathname))
	 (type (%pathname-type pathname))
	 (result (or name "")))
    (declare (simple-string result))
    (if (and type (not (zerop (length type))))
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	(concatenate 'simple-string result "." type)
	result)))

(defun directory-namestring (pathname)
  "Returns the device & directory parts of PATHNAME as a string."
  (setq pathname (pathname pathname))
  (let* ((directory (%pathname-directory pathname))
 	 (result (%device-string (%pathname-device pathname))))
    (declare (simple-string result))
    (when directory
      (setq result (concatenate 'simple-string result
				(the simple-string (%dirstring directory)))))
    result))

(defun host-namestring (pathname)
  "Returns the host part of PATHNAME as a string."
  (setq pathname (pathname pathname))
  (%pathname-host pathname))



;;;; ENOUGH-NAMESTRING

(defun enough-namestring (pathname &optional
				   (defaults *default-pathname-defaults*))
  "Returns a string which uniquely identifies PATHNAME w.r.t. DEFAULTS." 
  (setq pathname (pathname pathname))
  (setq defaults (pathname defaults))
  (let* ((device (%pathname-device pathname))
	 (directory (%pathname-directory pathname))
	 (name (%pathname-name pathname))
	 (type (%pathname-type pathname))
	 (result "")
	 (need-name nil))
    (declare (simple-string result))
    (when (and device (string-not-equal device (%pathname-device defaults)))
      (setq result (%device-string device)))
    (when (and directory
	       (not (equalp directory (%pathname-directory defaults))))
      (setq result (concatenate 'simple-string result
				(the simple-string (%dirstring directory)))))
    (when (and name (string-not-equal name (%pathname-name defaults)))
      (setq result (concatenate 'simple-string result 
				(the simple-string name))
	    need-name t))
    (when (and type (or need-name
			(string-not-equal type (%pathname-type defaults))))
      (setq result (concatenate 'simple-string result "."
				(the simple-string type))))
    result))



;;;; TRUENAME and other stuff probing stuff.

;;; Truename  --  Public
;;;
;;;    Another silly file function trivially different from another function.
;;;
(defun truename (pathname)
  "Return the pathname for the actual file described by the pathname
  An error is signalled if no such file exists."
  (let ((result (probe-file pathname)))
    (unless result
      (error "The file ~S does not exist." (namestring pathname)))
    result))

;;; Do-Search-List  --  Internal
;;;
;;;    Bind var in turn to each element of search list with the specifed
;;; name.
;;;
(defmacro do-search-list ((var name &optional exit-form) . body)
  "Do-Search-List (Var Name [Exit-Form]) {Form}*"
  `(dolist (,var (resolve-search-list ,name nil) ,exit-form)
     (declare (simple-string ,var))
     ,@body))


;;; Sub-Probe-File  --  Internal
;;;
;;;    Does the work of Probe-File, returning an additional value which
;;; indicates whether the name is really a file.
;;;
(defun sub-probe-file (pathname)
  (setq pathname (pathname pathname))
  (flet ((pathnamify (ns etype)
	   (declare (simple-string ns))
	   (case etype
	     (:entry_remote
	      (values (parse-namestring (concatenate 'simple-string ns "/"))
		      :entry_directory))
	     (t
	      (values (parse-namestring ns) etype)))))
    (let ((log-name (or (%pathname-device pathname) "default")))
      (if (eq log-name :absolute)
	  (let ((namestring (namestring pathname)))
	    (multiple-value-bind (name etype)
				 (mach:unix-subtestname namestring)
	      (if (null name) NIL
		  (pathnamify name etype))))
	  (if (null (%pathname-device pathname))
	      (multiple-value-bind (name etype)
				   (mach:unix-subtestname
				    (%ses-get-useful-name pathname))
		(if (null name) NIL (pathnamify name etype)))
	      (let ((namestring (%ses-get-useful-name pathname)))
		(do-search-list (entry log-name)
		  (let ((str (concatenate 'simple-string entry namestring)))
		    (declare (simple-string str))
		    (multiple-value-bind (name etype)
					 (mach:unix-subtestname str)
		      (when name
			(return (pathnamify name etype))))))))))))


;;; Probe-File  --  Public
;;;
;;;    Just call Sub-Probe-File and return nil when it isn't a file.
;;;
(defun probe-file (pathname)
  "Return a pathname which is the truename of the file if it exists, NIL
  otherwise.  Returns NIL for directories and other non-file entries."
  (multiple-value-bind (pn f)
		       (sub-probe-file pathname)
    (if (eq f :entry_file) pn)))



;;; Predict-Name  --  Internal
;;;
;;;    Predict-Name is a function used by Open to get an absolute pathname 
;;; for a file being opened.  Returns the truename of the file and
;;; whether it really exists or not.
;;;
(defun predict-name (file-name for-input)
  (let* ((pathname (pathname file-name))
	 (device (%pathname-device pathname))
	 (truename (probe-file pathname)))
    (cond ((eq device :absolute)
	   (if truename
	       (values (namestring truename) t)
	       ;; Try again in case file-name is a directory.
	       (predict-name-with-subtest (namestring pathname))))
	  ((and for-input truename)
	   (values (namestring truename) t))
	  (t
	   (let ((expansion (resolve-search-list (or device "default") t)))
	     (let ((name (concatenate 'simple-string (car expansion)
				      (%ses-get-useful-name pathname))))
	       (declare (simple-string name))
	       (predict-name-with-subtest name)))))))

(defun predict-name-with-subtest (name)
  (let ((gr (mach:unix-subtestname name)))
    (if gr
	(values gr t)
	(values (mach::simplify-file-name name) nil))))



;;; Rename-File  --  Public
;;;
;;;    If File is a File-Stream, then rename the associated file if it exists,
;;; otherwise just change the name in the stream.  If not a file stream, then
;;; just rename the file.
;;;
(defun rename-file (file new-name)
  "Rename File to have the specified New-Name.  If file is a stream open to a
  file, then the associated file is renamed.  If the file does not yet exist
  then the file is created with the New-Name when the stream is closed."
  (if (streamp file)
      (let* ((name (file-name file))
	     (pn (parse-namestring name))
	     (npn (merge-pathnames new-name pn))
	     (new (predict-name npn nil)))
	(when (mach:quick-subtestname name)
	  (multiple-value-bind (res err) (mach:Unix-rename name new)
	    (if (null res) (error "Failed to rename ~A to ~A, unix error: ~A."
				  name new (mach:get-unix-error-msg err)))))
	(file-name file new)
	(values npn pn (parse-namestring new)))
      (let* ((pn (or (sub-probe-file file)
		     (error "File to rename does not exist: ~S" file)))
	     (npn (merge-pathnames new-name pn))
	     (new (predict-name npn nil)))
	(multiple-value-bind (res err) (mach:unix-rename (namestring pn) new)
	  (if res (values npn pn (parse-namestring new))
	      (error "Failed to rename ~A to ~A, unix error: ~A."
		     (namestring pn) new (mach:get-unix-error-msg err)))))))

;;; Delete-File  --  Public
;;;
;;;    Delete the file, Man.
;;;
(defun delete-file (file)
  "Delete the specified file."
  (let ((tn (sub-probe-file file)))
    (when (streamp file)
      (close file :abort t))
    (if tn
	(let ((ns (namestring tn)))
	  (multiple-value-bind (res err) (mach:unix-unlink ns)
	    (if (null res)
		(error "Failed to delete ~A, unix error: ~A."
		       ns (mach:get-unix-error-msg err)))))
	(unless (streamp file)
	  (error "File to be deleted does not exist: ~S" file)))) 
  t)

;;; User-Homedir-Pathname  --  Public
;;;
;;;    If the user wants a meaningful homedir, she has to define Home:.
;;; Someday, login may do this for us.  Since we must always return something,
;;; we just return Default: if it isn't defined.
;;;
(defun user-homedir-pathname (&optional host)
  "Returns the home directory of the logged in user as a pathname.
  This is obtained from the logical name \"home:\".  If this is not defined,
  then we return \"default:\""
  (declare (ignore host))
  (let ((home (cdr (assoc :home *environment-list* :test #'eq))))
    (if home
	(pathname (if (string-equal home "/") "/"
		      (concatenate 'simple-string home "/")))
	(let ((expansion (if (search-list "home:")
			     (resolve-search-list "home" t))))
	  (if expansion
	      (car expansion)
	      (make-pathname :device "default"))))))

;;; File-Write-Date  --  Public
;;;
(defun file-write-date (file)
  "Return file's creation date, or NIL if it doesn't exist."
  (let ((tn (sub-probe-file file)))
    (when tn
      (multiple-value-bind (res dev ino mode nlink uid gid
				rdev size atime mtime)
			   (mach:unix-stat (namestring tn))
	(declare (ignore dev ino mode nlink uid gid rdev size atime))
	(if (null res) 0
	    (+ unix-to-universal-time mtime))))))

;;; File-Author  --  Public
;;;
(defun file-author (file)
  "Returns the file author as a string, or nil if the author cannot be
   determined.  Signals an error if file doesn't exist."
  (let ((filename (truename file)))
    (multiple-value-bind (winp dev ino mode nlink uid)
			 (mach:unix-stat (namestring filename))
      (declare (ignore dev ino mode nlink))
      (if winp (lookup-login-name uid)))))



;;;; DIRECTORY.

;;; DO-DIRECTORY searches a directory, binding the vars to the name and entry
;;; type.  Pattern and All are used in MACH:UNIX-SEARCH-DIRECTORY.
;;;
(defmacro do-directory ((name-var etype-var pattern &optional (all t) result)
			. body)
  "Do-Directory (Name Entry-Type Pattern [All] [Result]) {Form}*.
   If All is non-nil (the default), then Unix dot files to be processed.
   Unix dot and dot-dot are never processed."
  (let ((file (gensym))
	(res (gensym))
	(type (gensym))
	(p (gensym)))
    `(dolist (,file (mach:unix-search-directory ,pattern ,all)
		    ,result)
       (declare (simple-string ,file))
       (let* ((,p (position #\/ ,file :from-end t))
	      (,name-var
	       (if ,p
		   (subseq ,file (the fixnum (1+ (the fixnum ,p))))
		   ,file)))
	 (declare (simple-string ,name-var))
	 (unless (or (string= "." ,name-var) (string= ".." ,name-var))
	   (let ((,etype-var (multiple-value-bind (,res ,type)
						  (mach:quick-subtestname ,file)
			       (declare (ignore ,res))
			       ,type)))
	     ,@body))))))

(defun directory (pathname &key (all t))
  "Returns a list of pathnames, one for each file that matches the given
   pathname.  Supplying :all as nil causes this to ignore Unix dot files.  This
   never includes Unix dot and dot-dot in the result."
  (setq pathname (pathname pathname))
  (multiple-value-bind (dir pattern) (find-directory pathname)
    (let ((res ()))
      (do-directory (name etype pattern all)
	(if (eq etype :entry_file)
	    (let ((last-dot (position #\. name :from-end t)))
	      (push
	       (%make-pathname
		"Mach" :absolute dir
		(if last-dot (subseq name 0 last-dot) name)
		(if last-dot (subseq name (1+ last-dot)))
		nil)
	       res))
	    (push
	     (%make-pathname
	      "Mach" :absolute
	      (concatenate 'simple-vector dir (vector name))
	      nil nil nil)
	     res)))
      (nreverse res))))

;;; FIND-DIRECTORY returns an absolute directory vector for pathname as a
;;; first argument and an absolute namestring.  The namestring includes a
;;; trailing asterisk, wildcard, when the given pathname is immediately
;;; probe-able as a directory.
;;;
(defun find-directory (pathname)
  (multiple-value-bind (pn type)
		       (sub-probe-file pathname)
    (if pn
	(let ((ns (namestring pn)))
	  (declare (simple-string ns))
	  (case type
	    (:entry_directory
	     (when (char/= (schar ns (the fixnum (1- (length ns)))) #\/)
	       (setq ns (concatenate 'simple-string ns "/")))
	     (values (%pathname-directory (pathname ns))
		     (concatenate 'simple-string ns "*")))
	    (t (values (%pathname-directory pn) ns))))
	(multiple-value-bind (pn type)
			     (sub-probe-file
			      (make-pathname
			       :directory (%pathname-directory pathname)
			       :device (%pathname-device pathname)))
	  (unless pn
	    (error "Directory does not exist: ~S" pathname))
	  (let ((ns (namestring pn)))
	    (case type
	      (:entry_directory
	       (values
		(%pathname-directory pn)
		(concatenate 'simple-string ns (file-namestring pathname))))
	      (t
	       (error "~S is not a directory." pathname))))))))



;;;; Printing directories and determining file owner names.

;;; PRINT-DIRECTORY is exported from the EXTENSIONS package.
;;; 
(defun print-directory (pathname &optional stream &key all verbose return-list)
  "Like Directory, but prints a terse, multi-coloumn directory listing
   instead of returning a list of pathnames.  When :all is supplied and
   non-nil, then Unix dot files are included too (as ls -a).  When :vervose
   is supplied and non-nil, then a long listing of miscellaneous
   information is output one file per line."
  (setf pathname (pathname pathname))
  (let ((*standard-output* (out-synonym-of stream)))
    (if verbose
	(print-directory-verbose pathname all return-list)
	(print-directory-formatted pathname all return-list))))

(defun print-directory-verbose (pathname all return-list)
  (multiple-value-bind (dir pattern) (find-directory pathname)
    (declare (ignore dir))
    (format t "Directory of ~A :~%" pattern)
    (let ((dir-name (directory-namestring pattern))
	  (result ()))
      (do-directory (name etype pattern all (nreverse result))
	(let ((slash-name (if (eq etype :entry_file)
			      name
			      (concatenate 'simple-string name "/"))))
	  (declare (simple-string slash-name))
	  (when return-list
	    (push (pathname (concatenate 'simple-string dir-name slash-name))
		  result))
	  (multiple-value-bind 
	      (reslt dev-or-err ino mode nlink uid gid rdev size atime mtime)
	      (mach:unix-stat (concatenate 'simple-string dir-name name))
	    (declare (ignore ino gid rdev atime)
		     (fixnum uid mode))
	    (cond (reslt
		   ;;
		   ;; Print characters for file modes.
		   (macrolet ((frob (bit name &optional sbit sname negate)
				`(if ,(if negate
					  `(not (logbitp ,bit mode))
					  `(logbitp ,bit mode))
				     ,(if sbit
					  `(if (logbitp ,sbit mode)
					       (write-char ,sname)
					       (write-char ,name))
					  `(write-char ,name))
				     (write-char #\-))))
		     (frob 15 #\d nil nil t)
		     (frob 8 #\r)
		     (frob 7 #\w)
		     (frob 6 #\x 11 #\s)
		     (frob 5 #\r)
		     (frob 4 #\w)
		     (frob 3 #\x 10 #\s)
		     (frob 2 #\r)
		     (frob 1 #\w)
		     (frob 0 #\x))
		   ;;
		   ;; Print the rest.
		   (multiple-value-bind (sec min hour date month year)
					(get-decoded-time)
		     (declare (ignore sec min hour date month))
		     (format t "~2D ~8A ~8D ~12A ~A~%"
			     nlink
			     (or (lookup-login-name uid) uid)
			     size
			     (decode-universal-time-for-files mtime year)
			     slash-name)))
		  (t (format t "Couldn't stat ~A -- ~A.~%"
			     slash-name
			     (mach:get-unix-error-msg dev-or-err))))))))))

(defun decode-universal-time-for-files (time current-year)
  (multiple-value-bind (sec min hour day month year)
		       (decode-universal-time (+ time unix-to-universal-time))
    (declare (ignore sec))
    (format nil "~A ~2,' D ~:[ ~D~;~*~2,'0D:~2,'0D~]"
	    (svref '#("Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug"
		      "Sep" "Oct" "Nov" "Dec")
		   (1- month))
	    day (= current-year year) year hour min)))

(defun print-directory-formatted (pathname all return-list)
  (let ((width (or (line-length *standard-output*) 80))
	(names ())
	(cnt 0)
	(max-len 0)
	(result ()))
    (declare (list names) (fixnum max-len cnt))
    ;;
    ;; Get the data.
    (multiple-value-bind (dir pattern) (find-directory pathname)
      (declare (ignore dir))
      (do-directory (name etype pattern all)
	(let* ((slash-name (if (eql etype :entry_file)
			       name
			       (concatenate 'simple-string name "/")))
	       (len (length slash-name)))
	  (declare (simple-string slash-name)
		   (fixnum len))
	  (when return-list
	    (push (pathname (concatenate 'simple-string
					 (directory-namestring pattern)
					 slash-name))
		  result))
	  
	  (if (> len max-len) (setq max-len len))
	  (incf cnt)
	  (push slash-name names)))
      (setq names (nreverse names))
      ;;
      ;; Do the output.
      (let* ((col-width (1+ max-len))
	     (cols (max (truncate width col-width) 1))
	     (lines (ceiling cnt cols)))
	(declare (fixnum cols lines))
	(format t "Directory of ~A :~%" pattern)
	(dotimes (i lines)
	  (declare (fixnum i))
	  (dotimes (j cols)
	    (declare (fixnum j))
	    (let ((name (nth (+ i (the fixnum (* j lines))) names)))
	      (when name
		(write-string name)
		(unless (eql j (1- cols))
		  (tab-over 
		   (- col-width (length (the simple-string name))))))))
	  (terpri))))
    (when return-list (nreverse result))))



;;;; Translating uid's and gid's.

(defvar *uid-hash-table* (make-hash-table)
  "Hash table for keeping track of uid's and login names.")

;;; LOOKUP-LOGIN-NAME translates a user id into a login name.  Previous
;;; lookups are cached in a hash table since groveling the passwd(s) files
;;; is somewhat expensive.  The table may hold nil for id's that cannot
;;; be looked up since this means the files are searched in their entirety
;;; each time this id is translated.
;;; 
(defun lookup-login-name (uid)
  (multiple-value-bind (login-name foundp) (gethash uid *uid-hash-table*)
    (if foundp
	login-name
	(setf (gethash uid *uid-hash-table*)
	      (get-group-or-user-name :user uid)))))

(defvar *gid-hash-table* (make-hash-table)
  "Hash table for keeping track of gid's and group names.")

;;; LOOKUP-GROUP-NAME translates a group id into a group name.  Previous
;;; lookups are cached in a hash table since groveling the group(s) files
;;; is somewhat expensive.  The table may hold nil for id's that cannot
;;; be looked up since this means the files are searched in their entirety
;;; each time this id is translated.
;;; 
(defun lookup-group-name (gid)
  (multiple-value-bind (group-name foundp) (gethash gid *gid-hash-table*)
    (if foundp
	group-name
	(setf (gethash gid *gid-hash-table*)
	      (get-group-or-user-name :group gid)))))


;;; GET-GROUP-OR-USER-NAME first tries "/etc/passwd" ("/etc/group") since it is
;;; a much smaller file, contains all the local id's, and most uses probably
;;; involve id's on machines one would login into.  Then if necessary, we look
;;; in "/etc/passwds" ("/etc/groups") which is really long and has to be
;;; fetched over the net.
;;;
(defun get-group-or-user-name (group-or-user id)
  "Returns the simple-string user or group name of the user whose uid or gid
   is id, or NIL if no such user or group exists.  Group-or-user is either
   :group or :user."
  (let ((id-string (let ((*print-base* 10)) (prin1-to-string id))))
    (declare (simple-string id-string))
    (multiple-value-bind (file1 file2)
			 (ecase group-or-user
			   (:group (values "/etc/group" "/etc/groups"))
			   (:user (values "/etc/passwd" "/etc/passwd")))
      (or (get-group-or-user-name-aux id-string file1)
	  (get-group-or-user-name-aux id-string file2)))))

(defun get-group-or-user-name-aux (id-string passwd-file)
  (with-open-file (stream passwd-file)
    (loop
      (let ((entry (read-line stream nil)))
	(unless entry (return nil))
	(let ((name-end (position #\: (the simple-string entry)
				  :test #'char=)))
	  (when name-end
	    (let ((id-start (position #\: (the simple-string entry)
				      :start (1+ name-end) :test #'char=)))
	      (when id-start
		(incf id-start)
		(let ((id-end (position #\: (the simple-string entry)
					:start id-start :test #'char=)))
		  (when (and id-end
			     (string= id-string entry
				      :start2 id-start :end2 id-end))
		    (return (subseq entry 0 name-end))))))))))))



;;; Complete-One-File  --  Internal
;;;
;;;    Return as values a string and the greatest common prefix of all
;;; the files corresponding to pattern.
;;;
(defun complete-one-file (pattern default-type ignore-types)
  (let ((first nil)
	(length nil))
    (do-directory (name etype pattern nil)
      (declare (ignore etype))
      (let* ((last-dot (position #\. name :from-end t))
	     (type (if last-dot (subseq name (1+ last-dot)))))
	(cond ((and (not (string= type default-type))
		    (member type ignore-types :test #'string=)))
	      (first
	       (let ((msm (string-not-equal name first :end2 length)))
		 (when (and msm (< msm length))
		   (setq length msm))))
	      (t
	       (setq first name)
	       (setq length (length name))))))
    (values first length)))


;;; Complete-File  --  Public
;;;
;;;    If the pathname is absolute, just call Complete-One-File on and test
;;; whether the result is a file.  If a relative pathname, do it on each
;;; directory, accumulating the result.
;;;
(defun complete-file (pathname &key defaults ignore-types)
  "Attempt to complete Pathname as the name of a file.  If the resulting
  completion is unique, return T as the second value.  If there is no
  possible completion, return both values NIL."
  (setq pathname (pathname pathname))
  (setq defaults (if defaults (pathname defaults) *default-pathname-defaults*))
  (flet ((pathnamify (res len ambiguous pathname)
		     (values 
		      (make-pathname :device (%pathname-device pathname)
				     :directory (%pathname-directory pathname)
				     :defaults (parse-namestring (subseq res 0 len)))
		      (not ambiguous))))
    (let ((dev (or (%pathname-device pathname) "default"))
	  (default-type (%pathname-type defaults)))
      (if (eq dev :absolute)
	  (multiple-value-bind
	      (res len)
	      (complete-one-file (concatenate 'simple-string
					      (namestring pathname)
					      "*")
				 default-type ignore-types)
	    (declare (fixnum len))
	    (if res
		(pathnamify res len
			    (/= (the fixnum (length res)) len)
			    pathname)
		(values nil nil)))
	  (let ((namestring (%ses-get-useful-name pathname))		 
		(dirs (if (and (%pathname-directory defaults)
			       (string-equal dev "default"))
			  (list (directory-namestring defaults))
			  ()))
		(max most-positive-fixnum)